/*
 * #!
 * Ontopia Engine
 * #-
 * Copyright (C) 2001 - 2013 The Ontopia Project
 * #-
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * !#
 */

package net.ontopia.topicmaps.xml;

import net.ontopia.infoset.core.LocatorIF;

/**
 * PUBLIC: An interface that can be implemented by handlers that would
 * like to intercept external references in topic map documents.</p>
 */
public interface ExternalReferenceHandlerIF {

  /**
   * PUBLIC: Receive notification of a reference to an external topic
   * map.</p>
   *
   * @return The locator which should be used to resolve the
   * reference; if null is returned it will be interpreted as that the
   * reference should not be traversed.
   */
  LocatorIF externalTopicMap(LocatorIF address);

  /**
   * PUBLIC: Receive notification of a reference to an external
   * topic.</p>
   *
   * @return The locator which should be used to resolve the
   * reference; if null is returned it will be interpreted as that the
   * reference should not be traversed.
   */
  LocatorIF externalTopic(LocatorIF address);

}




